1. Field of Invention
This invention relates to an interventional catheter that is placed within vessels of the body to provide access and support for another interventional catheter having passage within it and delivered to the site of a lesion.
2. Description of Prior Art
Access to coronary arteries, carotid arteries, and some peripheral vessels of the body for percutaneous therapeutic and diagnostic catheters is often made via guide catheters that are placed through introducer sheaths which are positioned into vessels that are most easily accessed from outside of the body. Such access sites include the common femoral artery, the brachial artery, and the radial artery.
Positioning of the guiding catheter into the ostium of the vessel to be treated can often be difficult, especially in diseased vasculature or in vessels that require the catheter to undergo a significant turn in the direction of travel. An additional problem that often occurs when trying to advance the percutaneous catheters through the guide catheter is that the guide catheter does not provide enough support for delivery of the percutaneous catheter and can result in the guide catheter backing out from the ostium of the vessel leading to the lesion to be treated. This problem can be exacerbated if the interventional catheter is stiff or carries a stiff element such as a stent thereby requiring a larger radius of curvature in the guide catheter to allow delivery of the interventional catheter or device.
Carotid artery interventional therapy has typically been performed via a percutaneous femoral access with delivery of a guide catheter or sheath through the aorta to the ostium of the brachiocephalic artery or the left common carotid artery. In diseased aortas the access to these ostii can be difficult and the support provided by this access can be inadequate to allow advancement of the therapeutic catheter.
The access catheter of the present invention can be used to provide access for carotid artery intervention via a radial or brachial artery approach. It can also be used to provide access to vertebral arteries or cerebral arteries or for other vessels that require good support from the guide catheter that cannot be obtained via standard guide catheters. The access catheter can also be used in the femoral artery or iliac artery in order to provide for support in going over the aortic arch. Additionally the access catheter can be used in venous vessels of the body and in other tubular members of the body that are being treated via interventional or minimally invasive techniques and undergo a significant turn in the tubular member.
On the right side of the body the radial artery or other arteries of the right arm lead proximally to the right subclavian artery which combines with the right common carotid artery to form the brachiocephalic artery that joins to the aorta. Access via the right radial artery with an access guide catheter would allow easy and direct access to the common carotid artery to perform an angiogram or to deliver interventional devices that are able to negotiate a small radius of curvature. Interventional catheters that are stiff and cannot undergo a tight turn such as a stent delivery catheter system cannot be easily delivered directly via the subclavian artery to the right common carotid artery.
If one continues to follow the vasculature proximally down the common carotid artery and through the brachiocephalic artery and into the aorta there currently is not a good option available to turn back and reenter the brachiocephalic artery with a guide catheter, and one would not obtain the necessary support in order to allow passage of a stiffer interventional catheter such as a stent delivery system within such a curved reentering guide without backing out the guide catheter. An access guide catheter intended for radial access also must be of a small profile in order to properly traverse the relatively small radial arteries of the arm.
On the left side of the body the radial artery or other arteries of the left arm lead proximally to the left subclavian artery which joins to the aorta. Currently there is not a good device option available to negotiate the small radius of curvature turn with a guide catheter and direct an interventional catheter distally down the left common carotid artery which is adjacent to the left subclavian artery along the aorta. The current curved guide catheters would not provide the support necessary to allow a relatively stiff interventional catheter such as a stent system to extend distally down the left common carotid artery without backing out of the ostium and yet have the low profile necessary to traverse the radial artery.
Carotid artery and other interventional therapy have typically been performed via a percutaneous femoral access with delivery of a guide catheter or sheath. The femoral artery is reasonably large in diameter and placing an introducer and guide catheter here for standard coronary angioplasty and stent procedures is very common. However for delivering larger interventional devices from this site can require guide catheters and sheaths that are relatively large and can cause blood flow blockage. Similarly, delivery of an introducer and guide catheter via the radial artery can cause radial artery blockage if the therapeutic catheter is similar in size to the blood vessel that it enters.
Interventional catheters having a larger distal aspect are often delivered within a relatively small artery causing blockage of blood flow in the small artery. This is often the case for carotid stent delivery systems where the distal aspect of the therapeutic catheter is significantly larger than the proximal shaft. The radial artery is large enough to accommodate the smaller proximal shaft diameter however the distal aspect can be too large to safely fit within the radial artery.
What is needed is a guide catheter that does not block blood flow proximally in the smaller radial artery, but provides guidance of the larger distal aspect of the therapeutic catheter in the larger carotid artery that can accommodate the larger diameter guide catheter and distal therapeutic catheter.